package org.yelongframework.servlet.http;

import java.net.InetAddress;
import java.net.UnknownHostException;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang3.StringUtils;

/**
 * 默认实现
 * 
 * @since 1.0.0
 */
public class DefaultHttpServletRequestIPResolver implements HttpServletRequestIPResolver {

	@Override
	public String getRequestIp(HttpServletRequest request) {
		// 从Nginx中X-Real-IP获取真实ip
		String ipAddress = request.getHeader("X-Real-IP");
		if (StringUtils.isNotEmpty(ipAddress) && "unknown".equalsIgnoreCase(ipAddress)) {
			return ipAddress;
		}
		// 从Nginx中x-forwarded-for获取真实ip
		ipAddress = request.getHeader("x-forwarded-for");
		if (ipAddress != null && ipAddress.length() > 0 && !"unknown".equalsIgnoreCase(ipAddress)) {
			// 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
			int index = ipAddress.indexOf(",");
			if (index > 0) {
				ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
			}
			return ipAddress;
		}
		ipAddress = request.getRemoteAddr();
		if ("127.0.0.1".equals(ipAddress) || "0:0:0:0:0:0:0:1".equals(ipAddress)) {
			// 根据网卡取本机配置的IP
			try {
				ipAddress = InetAddress.getLocalHost().getHostAddress();
			} catch (UnknownHostException e) {
			}
		}
		return ipAddress;
	}

	@Override
	public String getRequestIpNonProxy(HttpServletRequest request) {
		return getRequestIp(request);
	}

}
